Electrolysis is a process whereby the electric current is used to promote the decomposition of contaminants in the influent. The use of an electrolytic cell in water treatment industry is known for years. These applications include production of required oxidants in the process and use them to eliminate harmful and unwanted organism. Most modern sewage treatment facilities and modern agriculture mature treatment facilities are using an initial anaerobic solids digestion step to generate methane gas to generation equipment to power the facility. A byproduct of the methane generation from organic materials is ammonia generation from urea and other organic nitrogen compounds in the effluent.
A problem with electrolytic base water treatment equipment is scale build up on electrode surface. As the treatment progresses, chemical fouling occurs due to oxidation reaction occurring at the anode and reduction reaction occurring at the cathode. The scale and fouling build up in the reactor requires higher current to maintain the same potential across the electrodes.
Electricity has been used for ages to cause electro-chemical reactions in the fluids. When current is passed through a solution using an anode and cathode separated by a finite distance, current, which is flow of electrons, flows through the solution. This induces redox chemical reactions at the anode and cathode as electrons are transferred to molecules and molecules are converted to ions in the solution and vice versa. Typically an EMF (electromotive force) source is used to send electricity through the solution and the current flowing through the solution is a function of the surface area of the electrode, distance between the anode and cathode, the potential difference applied, the nature of the electrodes and the nature of the medium through which the current is flowing. Efforts have been made in the past to pass as much current as possible to speed up the chemical reactions going on at the electrode surfaces by varying many of the above said factors. However, issues such as leakage current, cell efficiency over a prolonged period, precipitation of salts over electrodes, corrosion, scaling, mass transport limitations, durability and stability of electrodes have been some of the limitations that have been keeping the electrolysis costs prohibitively high.
The present disclosure addresses some of these issues in an attempt to bring down the costs of electrolysis in the context of waste water treatment such as frac water, flow back water etc.